


Coveting Eyes

by Mabel_Juice



Category: Gravity Falls
Genre: Alternate Universe - Canon Divergence, F/M, Incest, M/M, Multi, Other, Spying, Voyeurism
Language: English
Status: In-Progress
Published: 2016-11-30
Updated: 2016-11-30
Packaged: 2018-09-03 06:02:48
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 4,729
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8700241
Author URL: https://archiveofourown.org/users/Mabel_Juice/pseuds/Mabel_Juice
Summary: Somewhere lost in the confusing whirlwind of puberty, Gideon's twisted romantic desires had shifted. The objects of his desire are too caught up in their own demon deal filled drama to notice the messy amateur magic invading their lives.





	1. The Ooze

**Summary for the Chapter:**

> Gideon is a disgusting little freak, Dipper dirties a sock, and Mabel is hiding something.

**Notes for the Chapter:**

> I wrote this forever ago, like I think around the time Northwest Mansion Noir aired. So for that reason there's some obvious conflict with canon. I think that might have been one of the things keeping me from publishing it way back when? I don't know... Let me know what you think.

Somewhere lost in the confusing whirlwind of puberty, Gideon's twisted romantic desires had shifted. Not dwindled in the least, just... shifted. It was difficult to pinpoint exactly when it had happened. Maybe it was because there was hardly a voyeuristic session of his without the presence of one twin or the other. But at age 18 -using magic to hide in plain sight among an arsenal of glitter, yarn, and various craft supplies in the Pines' twins still shared bedroom-, it was impossible to deny that he was a little turned on by the picture laid out in front of him. 

Dipper Pines furiously attempting to rub one out before his sister came upstairs. He was clearly prepared for someone to walk in on him, covering most of the sight with his blanket. Little gasps escaped him, but he was able to keep impressively quiet. 

'He wouldn't be able to stay quiet if I got my hands on him.' Gideon smirked at the thought. 

There was something awfully intriguing about the boy. Not in the same way Mabel was, but the feeling was there nonetheless. Dipper had an intelligence that Gideon might have said rivaled his own, and that secretly, he envied hotly. But even though Dipper held intellectual pursuits as close to his heart as to his mind, on the outside he looked more like a work-out junkie. Not disgustingly muscular or anything, just obviously athletic. All of his clothes were loose enough to breath, and tight enough not to snag on branches. Upon close inspection, it was obvious he wasn't afraid to get his hands dirty either. Stains littered the material, mud, sweat, and sometimes what looked suspiciously like blood. His palms were permanently discolored a few shades too dark, and his fingernails perpetually had dirt caked underneath. It worked well for him, though. Rugged, brooding, all solid muscle and brute MAN. 

Mabel, on the other hand. She was the embodiment of warmth, innocence, creativity, and beauty. Everyone she met was instantly put under the spell of her smile and positivity. Unlike her brother, she prospered in the company of strangers. If ever anyone could be termed a social butterfly, it was her. Flitting from one person to the next, going out of her way to spread her radiant happiness. She'd grown into quite the lady, and though she was more than happy with her body, she believed whole heartedly that modest comfort and style could live in harmony. 

Mix that in with both of the Pines' shared determination and refreshing -if naive- morals, and Gideon was swooning. 

It made sense to him, in a way. After all, he'd always fancied himself a collector. When he was younger he'd had been obsessed with a set of little ceramic unicorns in a local shop. His dad would buy him one or two whenever the budget allowed, but Gideon wasn't happy until he was sure that he owned every single one. Than he hoarded the figurines away in a glass cases, often opening it just to touch them. Prove to himself that they were, in fact, all his and no one else's. Long since broken in a childhood fit of rage, the Pines were his new unicorns. Why settle for just one when he could have the full set? It seemed rude to split up such a pair, anyway. 

So he wouldn't. He'd take both of them for himself. Make them see how good of a lover- no, owner- he could be. Gideon would admit there had been a couple minor setbacks in his plans. Magic was harder than the books made it look. He always missed some minuscule detail that threw the entire thing askew, or lacked the power needed to cast the spells he wanted. It annoyed him to absolutely no end. But no matter, he felt good about tonight. He'd have those sweet little brunettes on their hands and knees by the end of the week if this worked. Sixth time's the charm. 

For the moment though, Gideon was content to watch Dipper come to a muffled finished. His body fell loosely against his bed, and he stared up at the ceiling with a flushed face, and vacant smile. After a moment, he leaned over to throw a bundled up sock underneath his bed. Oh. Oh gross. 

Gideon wondered vaguely if anyone would notice if he stole that sock later. 

Dipper's timing was impeccable, just able to straiten himself up fast enough to appear innocent as Mabel flounced into the room. "Mabel has arrived," she cried, going over to plop herself down on his bed, "Are you awake enough for braid time?" 

Dipper laughed, and Gideon could tell there was a hint of nervousness in it. Probably worried his sister would be able to sense what he'd just been doing. "Yeah alright," he conceded, "But not my beard." 

Mabel pursed her lips, puffed up her cheeks, and widened her eyes, coming close enough to stroke her brother's facial hair, "One day, my precious, one day. Dipper will let us put beads and glitter in you and it will be glorious." 

"Oh my God," Dipper smiled and blushed, but pushed her away by the face, "Stop, you look like a demented fish." 

The twins braided one another's hair into tiny little parts that stuck up at odd angles. Their task was accompanied by filling one another in on their separate days. Mabel had turned the shack into the location of her -quite popular- online store. Most of her money came from the designs she sold to larger companies, but there was nothing quite like the doing custom work, and personally getting to see the customer's face light up. 

Today, she'd worked on an order for pink knitted footie pajamas. She fully endorsed this idea however strange, and difficult it might've been to make. She didn't use the title 'Ultimate Knitting Master' lightly. 

Dipper spent his days cataloging the supernatural. No one believed any of his research, of course- not outside of Gravity Falls, anyway. But he had a little underground cult following of young adults who ate up his published journals under the impression that they were works of fiction. Naturally, he'd been exploring the cliffs near the falls on the other side of town, trying to decide what the discoloration in the sediment could mean. 

The twins weren't the richest, but they were doing what they loved, and they always had one another.

A thought struck Dipper as he worked Mabel's long locks between his dexterous fingers. "Cindy," Gideon gagged at the name of Dipper's ex-girlfriend, "She... she said something during one of our fights that I haven't been able to stop thinking about..." he started out hesitantly. Mabel hummed a reply. 

"She told me it's weird that we still sleep in the same room." 

Mabel visibly stiffened, and than relaxed, "So what if it is?"

"Well..." Dipper bit his lip trying to put this delicately. He wished he could be as uninhibited as his sister. How did she always ignore the judgmental stares? The whispers? "Don't the guys you go out with ever say anything about it?" he asked, not really thinking too hard on the fact it had been a while since Mabel had actually brought anyone home. 

Mabel turned her head slightly despite the work Dipper was doing on her hair, a frown set onto her sad face, "Of course they do. But I don't care. Why should we shove a barrier between the 21 year old mystery duo just to make some butts we barely talk to a little more comfortable? That'd be dumb." 

"Yeah, I guess you're right," Dipper relented. 

"I'm always right!" Mabel chirped, bouncing, and inadvertently tugging her own hair. 

Gideon watched the display, fascinated as always. He went over his plan once more in his head, waiting patiently for them to fall asleep. It took a while. Even after they turned the light out, they spoke in hushed voices with one another about anything and everything for nearly another hour. They ended up both sleeping in Dipper's bed that night, unabashedly wrapped in one another's arms, braided hair splayed out madly. It was only a matter of time before he had these two strange, lovely creatures in his grasp. 

After retrieving the dirtied sock from under the bed, Gideon snuck downstairs, into their kitchen. Latex gloves snapped onto his sweaty hands, and he produced a carefully sealed package of what appeared to be clear jelly. In the dark, the goop had an iridescent glow to it. He reached into any open container he could find in their refrigerator, and slathered the smallest, barely noticeable amount of the strange substance onto all of their food. 

Yes, soon the Pines would be throwing themselves at his feet.


	2. Dream a Little Dream of Me

**Summary for the Chapter:**

> Dipper's incestuous dream date turns into a dark carnival.

**Notes for the Chapter:**

> I had imagery from Something Wicked This Way Comes in mind while writing this out. I mean there's a lot of parallels between it and Gravity Falls anyhow, but I went full Bradbury on this chapter. ...I had fun writing Bill, but reading back over it I'm not sure how much I like my interpretation of him...

Dipper often had dreams he was less than proud of. Most of these included getting a little closer to his sister than was appropriate. Nothing that bad happened most of the time. Just. A less than platonic kiss here, a sexually charged date there. 

Of course. There was the occasional night that seemed bent on steering the twin's dates strait into 'too hot for television' territory. Luckily Dipper always woke up before he and Mabel took the plunge. However frustrating it might've been for the admittedly larger part of him that enjoyed these dreams, he was grateful they never went all the way. It wouldn't be easy to look Mabel in the eye after his subconscious weaved something like that together. 

Tonight's dream seemed pretty normal so far. He and Mabel were at the carnival. So what if they were holding hands? That wasn't even that bad. Twins do that! 

The sky was completely black, but the colorful electric lights that blinked around them were too cheerful for the surroundings beyond to be eerie. They went from one attraction to the other, riding kiddie rides and winning poorly made stuffed animals for one another.

Soft music played at a steady decibel level no matter where they ventured. A nice upbeat piano tune reminiscent of something an ice cream truck would play. Every so often the song would become garbled or perhaps the piano player would miss a note, and a chill would go down Dipper's spine. 

If Mabel noticed, she didn't let on. Her wild grin never left her face, even as she enthusiastically pulled Dipper over to the maze of mirrors. His dream mind didn't question why there were no employees, or other patrons. Just laughed at his sister's childish eagerness to go through the maze. 

They crashed and banged into the walls, their feet creating metallic echoing through the reflective hallway as they hit the ground. Somewhere along the line, they'd stopped their giggling. The wonky hallway began to narrow, less real openings presenting themsleves. Finally, Dipper couldn't even find the direction they'd come from. Only reflection after reflection of him and his sister holding hands. The images condemned their closeness, threw it back at them relentlessly. Dipper squeezed Mabel's hand, "Uhm. Where's the exit?" 

"I don't..." Mabel's words were swallowed and her hand fell out of his. 

"Mabel?" Dipper turned sharply to see his sister pressing her hands up against the the opposite side of the mirror, starring at him in horror, "Mabel!" He banged on the glass desperately. One of his punches landed with a horrible crack, and despite the blow not being anywhere near hard enough to break this thick of glass, the entire mirror shattered.

With each heavy breath that escaped him, he realized in horror that the three remaining mirrors and now blank cement wall his sister had disappeared behind were closing in on him. He shouted his sister's name desperately, scratching at the wall. The music was blaring and quick now, enough notes corrupted that it was difficult to even tell what was being played. Seeing his own distorted, frightened red face reflected back at him a thousand times dizzied him, made him want to hurl. The mirrors were upon him, limiting his movements, starting to squeeze hard enough to threaten bodily harm. He shut his eyes, prepared for the end.

Suddenly, everything stopped. 

A grating, but apologetic voice suddenly cut through the music, "Sorry about the dramatics there, kid. No reason to make YOU shit your pants when it's your sister I'm after."

Dipper's eyes shot open. He was back in the carnival, sitting in a grass plot right out of the mirror maze. Only the color had been drained from the lights. "What..." he whispered, grasping at his forehead, he stood up and yelled toward the sky, "What do you mean you're after Mabel? What do you want from her?" 

There was momentary silence, as if the voice was trying to decide if it should entertain his question, "Nothing she didn't agree to. She took out a hefty loan, and it's time to pay up. That's all." 

"Don't you DARE hurt her!" Dipper yelled back reflexively, searching the clearing for somewhere the creature could be hiding. 

"Ugh. You two are ridiculous, I swear," the voice raved, "I usually don't condone honesty, but damn. I think you kids could use a dose of it." 

"What are you TALKING ABOUT?" Dipper demanded, "Stop being so damn cryptic and show yourself!" 

"What's the magic word?" the voice sang out teasingly. 

"Are you fucking serious...?" Dipper muttered to himself before yelling out, "Please?"

Even though he hadn't noticed it before, Dipper certainly noticed it now. The only color left in the world came from the neon yellow sign that loudly buzzed over the mirror maze. Instead of the attraction being labelled with any words, the sign held only a singular glowing triangle in the center. His attention was drawn to it when a blast of embers shot from it's surface. 

Realization dawned on Dipper as the shape flashed, and sprang to life. The voice, the creepy dream, the loss of color. It was all painfully familiar. It hardly surprised him when the triangle's eye opened wide, settled on him, and wrinkled in a way that connotated smiling. 

"Hiya, Bill Cipher, remember me?" Bill asked cheerily, coming up and offering a stretched out hand. Dipper glared at the demon, and defensively pulled his arms into himself. A peeved expression scrunched Bill's eye, but he quickly brushed it off. His bitter laugh echoed around them, "I'll take that as a 'yes'."

"Just tell me what you did with Mabel," Dipper bit out. 

Bill shrugged dismissively, his body flashing to a black and white view of Mabel and him talking, "Like I said before... We made a little DEAL, and the due date to pay off her debt has passed, so I'm here to collect." The sentence ended with a translucent blue Mabel getting pulled from the image. She screamed silently before bursting into a cloud of smoke. 

"You're going to take her soul?" Dipper blanched, feeling sick. 

"It wasn't on the original agenda, but yeah," Bill zoomed in closer to Dipper's face. His eye was lowered in a vaguely flirtatious way. Which made the flick to Dipper's nose all the more off-putting, "But since I'm SUCH a nice guy, I'm gonna give you -yes YOU- a once in a lifetime chance to save her!" 

"But... but... This doesn't make any sense!" Dipper argued, tugging at his matted curls, "Why would she make a deal with you? What WAS the deal? Was that really Mabel in my dream than? You can't expect me to agree to anything without-" 

"Zip it." 

The flow of Dipper's words was cut off by a literal zipper closing his lips together. Muffled protesting continued to come from him, and Bill irritatedly smacked him with his cane to shut him up completely. 

"Trust me when I tell you that this deal is weighted WAY in your favor. I don't usually offer people a way out like this. But. I LIKE you. And you can either agree to my demands -without prior knowledge of a few little details- or live the rest of your miserable life knowing that you're the reason your sister is a soulless husk," his voice dropped a few octaves as he flashed red, "GET IT?" 

Dipper, wide eyed, nodded profusely. With a quick snapping motion, Bill's hand was coated in blue flames. There was only a moment's hesitation in Dipper as he stared into the blue light, and thought back to the first time he'd made a deal with Bill. It hadn't exactly worked out in his favor. But last time, he'd made the deal out of spite. This time, he was doing it for love. Maybe... maybe that would be the thing that saved him. Slowly, Dipper took the demon's little hand in his own. The flames licked at him, sealing his fate. 

The zipper on his mouth dissipated, and he narrowed his eyes. "So do you mind telling me what exactly it is I just agreed to?" 

Bill hummed, "You're gonna KILL Preston Northwest for me." An image of Pacifica's dad flashed onto Bill's surface, Xs over his eyes. 

Dipper's mouth fell open, "WHAT?" 

"You heard me! One dead Northwest daddy, or I get to reap your soul," Bill put a hand on his shoulder and leaned toward his ear as if he were whispering a secret, "Oh and, a word to the wise: you really outta throw out all the food in your house. And I mean ALL of it. Unless it's secretly your life long dream to have your noggin busted up like another one of that living ventriloquist dummy's unicorns." 

Dipper's nose scrunched in confusion, "Excuse me?" 

"Ugh, I should start charging you for these answers, Faust," Bill twisted himself away, "Take a look in the potions manual in the bottom drawer of your nightstand. Page 34. And be quick about it, Shooting Star is already up and at'um. I don't mean to toot my own horn, but she just had QUITE a nightmare courtesy of YOURS TRULY, and I know I don't need to tell you that she's a stress eater." 

Bill pulled Dipper forward by his beard, and instructed lowly, "Now go on and pop your killing cherry for me, sweet cheeks." His tiny hand flitted back and forth a few times, shaking out some glitter and making an odd magic twinkle sound effect. Than all at once the dainty appearance came crashing down as Bill slapped him across the face with a surprising force that sent Dipper spiraling from the strange carnival scene.


	3. The Most Important meal of the Day

**Summary for the Chapter:**

> Dipper wakes up, Mabel's about to eat a delicious and nutritious bagel, and the incest dial gets turned up from maybe 3 to like 9.

When he opened his eyes, Dipper found he'd fallen on the floor next to his bed. He blinked a few times to rid himself of the last remnants of sleep. Than, since the drawer was level with his vision and very much in reach, he pulled the dilapidated old potions book out of the bottom of his nightstand. The old tome had totally been worth helping the Hand Witch and her fiancé move into an apartment across town. It was filled with pictures, and ridiculously in depth explanations into the who, what, when, where, why, and how of each potion. 

Page 34. There was an even longer history of the magic's invention than most of the items had. From Dipper's skimming he gathered that some sociopathic ruler from way, way back had commanded a wizard to mix together what essentially sounded like the ultimate date rape drug. The -really disgusting- concoction rendered the subject completely subservient, and instilled within them -Dipper's face heated up- "an insatiable desire for pleasures of the flesh."

Dipper started to put the pieces of Bill's warning together. "Oh shit," his dry, morning-mouth cursed. He quickly untangled himself from his sheets, and got up so fast that he nearly tripped over his own feet. "Mabel!" he yelled, running into the kitchen. 

He bounced against the kitchen entrance, and skidded across the floor to a halt. There was Mabel, standing at the counter, cream cheese coated bagel in hand. She turned and quirked a brow at him, "What's got you all panicy?" There was a small smile on her face, but it was forced, and the bags under her eyes revealed the truth of her restless night. He'd think on that later. 

"Mabel don't eat that!" Dipper shouted wildly. 

Mabel looked at the bagel, to Dipper, back at the bagel, and sort of laughed. "I know I asked you to call me out when I'm about to cheat on my diet, but don't you think you're going a teensy bit overboard there?" 

"What? No. NO-" Dipper gasped as Mabel continued to lift the food to her mouth, and quickly stepped forward to slap it out of her hand. The bagel landed on the ground cheese-down with a SPLAT. Mabel looked like- well, frankly she looked like someone who just got their breakfast slapped out of their hand. "Would you just listen to me? It was drugged!" Dipper raved. 

With a pouting lip, Mabel let out a hurt little whimper while holding her lightly assaulted hand defensively, "Well. You still didn't have to throw it on the floor!" 

"This is serious!" Dipper held up the potions manual and pointed frantically at the Byzantine-esque stylization of a man getting blown while two more woman dazedly hung off of him, "Some creep might've put THIS in our food." 

Mabel narrowed her eyes, "How do you know?" 

"Bill-" he lowered his book onto the table as he considered that for a second. It was very possible that Bill had just been fucking with him. But... better safe than sorry, right? "Bill told me," he finished his explanation. 

The demon's name felt bitter on his tongue, only serving to remind him of his other frustrations. No time like the present to do some questioning, "And speaking of Bill, do you want to tell me what the Hell is going on? Why would you make a deal with him?" 

He was pretty butt-hurt about that. Not Mabel making the actual deal; he had to assume she had a good enough reason for that. It was the fact that she didn't tell him. They told one another everything! How could she keep something so huge from him? 

"I-" Mabel's voice faltered. She looked away from her brother sheepishly, "You made a deal with him once too, you know." 

"Okay. First of all, I was twelve. Second, we're talking about YOU right now. I'm supposed to murder a man- MURDER- to save our skins, and I really feel like I deserve an explanation as to why that is." 

"You have to murder...?" Mabel muttered, and understanding passed through her expression. It quickly turned to anger, "What did you DO?" 

"What did 'I' do? I did the only thing I could DO! He was going to take your soul, and he offered me a way to stop it. Excuse me for caring about you a little too much to let something like that happen-" Dipper stopped his incredulous rant when he noticed Mabel had turned her head down, and started to shake with sobs. 

"Hey," he murmured quietly, pulling her into his chest. She let him, but kept shaking, audible whimpers escaping, "Mabel..." his tone was stern, but he gently stroked her -still braided- hair nonetheless, "I don't understand how you could agree to kill anyone." 

"I was never going to kill Pacifica's dad," Mabel choked out, "I just said that because it's what that stupid triangle wanted. But I knew that if I didn't, he would just take my soul. I was fine with that! You should've... You should've let it happen, Dipper!" 

"Why would you willingly give your soul to a demon?" 

"Because I'm going to Hell anyway," she wailed miserably into the crook of Dipper's neck. 

Those words hurt him a little. None of this made any sense. How could this wonderful, generous girl think that about herself? If there was one thing Dipper was sure of, it was that his sister was a good person. Better than him, and he didn't think HE was going to Hell. "No you're not," Dipper ground out.

"Yes I am! You don't know what goes on in my head. I'm a terrible person." 

"Shut up," Dipper hugged her tighter, as if to make her understand how much she meant to him. How loved she was. They stood there, grasping onto one another in the middle of their kitchen. The clouds broke away from one another to give way to dawn's warm glow. On the tree line, the red sun blinked down at them. An all seeing eye casting it's light onto the twins. Silence spread comfortably, and the high tensions sunk down. 

After the ticking of the grandfather clock on the hallway became too much, Mabel spoke up again, "I don't deserve this," her voice came out more even now, "I don't deserve you." 

"That's ridiculous, Mabel..." they rocked back and forth slowly, and he tiredly asked, "Are you going to tell me what your deal WAS?" 

Dipper couldn't see the motion, but could feel Mabel shake her head against him. "You'd hate me." 

"I could never hate you."

She pulled away from him, and looked him in the eye for the first time since she started to cry. Her tired face was still puffy, red, and wet, but her voice was like steal, "Maybe if I tell you, you'll let me give up my soul instead of committing murder." 

Dipper wiped some of the tears off her face, "Try me." 

"You know how I haven't dated in like half a year?" He nodded, and Mabel took in a deep breath, "It's because of you," she grabbed onto her brother's shirt, gaze shifting away from him only momentarily, "How I feel about you, I mean. I don't want to be with anyone else. Everyone else just seems stupid and boring." 

"And I..." Mabel backed away from Dipper, who's first instinct was to reach out and grab her hand, but he thought better of it. Tears were already welling up again on her face, "I wanted you to touch me, hold me, do... ya know... not sibling grown up things? But I couldn't ask you to do that. So. When the evil isosceles guy showed up and told me he could help me live it all out in my dreams..." 

Dipper straitened up. Was that why he'd been having those dreams? Oh man. It wasn't like he didn't like them, and he hadn't felt half as bad as Mabel about all of this... If he'd been more upfront, they could have figured out that they were in this mess together. It would already be too late to get them out of their entanglement with Bill, but at least Mabel might be in a less self destructive state of mind.

"Mabel," Dipper put his hand on her shoulder, "I don't know how or why. But I'm almost positive we've been dream sharing. All those... all those dates, and kisses, that really happened. I mean not really, really-" he cut himself off. His gaze implored her to understand, and searched for the right words as if they would be written in her expression, "but since we were sharing those experiences together, than it must count for something. I mean. What I'm trying to say is- I think..." he interlaced his fingers with Mabel's, "I feel the same way about you." 

That was all Mabel needed to hear. She all but pounced on her brother, wrapping her arms around him, reveling in his warmth. Their lips crashed together. It felt familiar, but so much more tangible now. Real. The lust they'd felt in the dreamscape intermingled and exploded with the twin's overwhelming love for one another. Waves of electric joy prickled down through Mabel. Down her arms, and to her fluttering stomach. The moment was beautiful, and tingly, and so painfully bittersweet. She tried and failed to keep in both her stupid, relieved grin, and anguished tears. 

Eventually -though they hadn't moved their bodies an inch away-, they were no longer kissing. Just standing their in the old rickety kitchen, holding onto one another like it was the only thing that could keep them grounded. 

The pink light of dawn was broken by a shadow that passed slowly over Dipper's face. If he noticed, he disregarded it instantly. Probably just a cloud.


End file.
